1 John 3:10

3:10 By this the children of God and the children of the devil are revealed: Everyone who does not practice righteousness – the one who does not love his fellow Christian – is not of God.

1 John 3:14-15

3:14 We know that we have crossed over from death to life because we love our fellow Christians. The one who does not love remains in death. 3:15 Everyone who hates his fellow Christian is a murderer, and you know that no murderer has eternal life residing in him.